There are a number of strong themes in this story. One is the theme of childlike innocence: the idea that children are too innocent to understand the evil that adults are capable of. Another is the theme of denial: that people are capable of denying the nature of their actions or able to delude themselves into thinking their actions are positive or beneficial even when they are in fact harmful or evil. Another theme seen in the story is that of compassion: various characters choose to behave compassionately in the wake of many acts of cruelty.

uhm. I think the author alsoo focuses on the Child's innocence and curiosity, because children are widely known as the most curiuos people that's why they try all the things they want to get tha answer for their question. and also "friendship" because these two boy that are actually friends are the instruments of the author to clearly show us that there are many hidden and mysterious things in this world and one of these are about the Holocaust. these two boys treasured they're friendship to the end and even though it was a tragic movie/story it is very touching and very true for children who are very innocent for the happenings in this world. they are the one who made the people realize that such innocence has brought us into reality, the rality that this world is not just about happiness but the reality that THIS world is full of mysteries.